Inertia and load responsive device for limiting braking pressure

Claim 1

In an automobile braking system, a device limiting braking pressure comprising a limiter body which has an inlet orifice and an outlet orifice and a valve mounted therein for cutting off said inlet orifice from said outlet orifice, a movable piston subject to the hydraulic pressure at said inlet orifice, an inertial mass disposed within said body for movement with respect to said body in response to deceleration of a vehicle carrying the system and operatively associated with said valve load-sensitive means, and elastic means for co-operation with said inertial mass and said piston, said load-sensitive means cooperating via a group of elastic members with said inertial mass and with said piston in the direction in which said valve opens, and the force of the pressure at said inlet orifice being exerted against a working face of said movable piston in opposition to the contrary force exerted by a load, said valve being closed as a result of the effect of hydraulic pressure and inertial force acting upon said inertial mass at a predetermined vehicle deceleration, the closure of said valve at said predetermined vehicle deceleration being established by the resultant of a plurality of forces including the hydraulic pressure force acting on said piston, the inertial force acting upon said inertial mass upon deceleration of the vehicle, a pre-load force corresponding to vehicle load and applied to said piston through one of said elastic members in a direction opposing said hydraulic pressure force.